<!-- 应用头部组件 -->
<header class="app-header" id="app-header">
  <div class="header-content">
    <div class="app-title">
      <h1 class="title-text">
        🌊 RAG 聊天助手
      </h1>
    </div>
      <!-- 导航按钮区域 -->
    <div class="header-nav">
      <button id="chat-nav-btn" class="nav-btn active" title="聊天">
        💬 聊天
      </button>
      <button id="sessions-nav-btn" class="nav-btn" title="会话列表">
        📋 会话
      </button>      <button id="document-nav-btn" class="nav-btn" title="文档管理">
        📄 文档管理
      </button>
      <button id="workflow-nav-btn" class="nav-btn" title="工作流">
        🔄 工作流
      </button>
    </div>
    
    <!-- 会话列表下拉框 -->
    <div id="session-dropdown" class="session-dropdown hidden">
      <div class="session-dropdown-content">
        <div class="session-header">
          <h3>会话列表</h3>
          <button id="close-session-dropdown" class="close-btn">✕</button>
        </div>
        <div class="session-list" id="session-list">
          <div class="loading-indicator" id="session-loading">
            <div class="spinner"></div>
            <span>加载中...</span>
          </div>
        </div>
      </div>
    </div>
    
    <div class="header-actions">
      <button id="theme-btn" class="action-btn theme-btn" title="切换主题">
        🎨
      </button>
      <button id="settings-btn" class="action-btn settings-btn" title="设置">
        ⚙️
      </button>
    </div>
  </div>
</header>
